Hitachi HUS154530VLF400 User Manual

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Hitachi Ultrastar 15K450 (FC-AL) Hard Disk Drive Specification
207  
19.14  PRE-FETCH (34)
Table 174: PRE-FETCH (34)
The PRE-FETCH command requests the drive to transfer data to the cache. No data is transferred to the Initiator.
Transfer length field specifies the number of contiguous blocks of data that are to be transferred into the cache. A 
transfer length of zero indicates that blocks are to be transferred into the cache until the segment is filled or until the 
last block on the media.
Immed (Immediate) must be zero. An immediate bit of zero indicates that the status shall not be returned until the 
operation has completed. 
If the Immed bit is set to one, the drive returns a Check Condition status. The sense key shall be set to Illegal 
Request
 and the additional sense code shall be set to Invalid Field in CDB.
Byte
Bit
7
6
5
4
3
2
1
0
0
Command Code = 34h
1
Reserved = 0
Reserved = 0
Immed 
= 0
Obso-
lete
2-5
(MSB) 
Logical Block Address
(LSB)
6
Reserved = 0
7-8
(MSB)                                            Transfer Length
                                (LSB)
9
VU = 0
Reserved = 0
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